In optical tape recorders of the type described in the article "Optical Tape System; evaluation of recorder and media" by G. W. R. Leibbrandt, J. A. H. Kahlman, G. E. van Rosmalen and J. J. Vrehen in SPIE Proceedings Series, vol. 3109, use is made of a rotating polygon mirror, for example a polygon having 10 facets, which images a laser beam directed onto the polygon via an objective on an optical tape. The plane of the polygon mirror is substantially perpendicular to the travel direction of the tape, and the information is recorded in narrow, parallel tracks on the tape. In the longitudinal direction of a tape having a width of, for example 12.7 mm, for example, 12 tracks of 1 mm may be present. Each track consists of parallel sub-tracks located transversely to the longitudinal direction of the track, and each sub-track is recorded during the rotation of one facet of the polygon mirror by the laser beam, and the next, juxtaposed sub-track is recorded during the rotation of the next mirror facet by the laser beam.
For example, 1500 bits can be recorded on each sub-track by modifying the surface of the tape by means of the laser beam, for example by forming pits on this tape in a way which is comparable with the method used for a compact disc. When reading the pits by means of the same laser beam, these pits have different reflection properties than the interposed areas, and the signal recorded on the tape can be derived from this information.
The above citations are hereby incorporated in whole by reference.